Refrigerating apparatus



April 20, 1943. L. A. PHILIPP REFRIGERATING APPARATUS Filed Nov. 25, 1940 x a 0 W d v m MW 0 U I], l 7 W W .I, a

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Patented Apr. 20, 1943 UNITED STATES. PATENT. OFFICE REFRIGERATING APPARATUS Lawrence A. Philipp, Detroit, Mich, assignor to Nash-Kelvinator Corporation, Detroit, Mich a corporation of Maryland Application November 25, 1940, Serial No. 366,990

1 Claims. (Cl. 62-116) This invention relates to refrigerating apparatus, and, more particularly, to refrigerating apparatus of the multiple temperature type.

One of the objects of my invention is to provide an improved refrigerating apparatus which maintains a food compartment at a relatively high refrigerating temperature and a relatively high humidity and at the same time maintains a freezing compartment at a relatively low temperature.

Another. object of my invention is to provide an improved refrigerating apparatus which ineludes an insulated cabinet having a low temperature compartment located within a food storage compartment, a primary refrigerating system having a refrigerant evaporator located within the low temperature compartment for rapid freezing of ice cubes and the like and for maintaining relatively low refrigerating {temperatures throughout the compartment, and a secondary refrigerating system having a refrigerant evaporator which substantially encloses the entire food compartment for maintaining a relatively high and uniform refrigerating temperature in said compartment and having a condenser associated with the primary refrigerant evaporator for condensing refrigerant evaporated in the secondary system.

Another object of my invention is to provide an improved arrangement for the ready removability of the aforesaid primary refrigerating system as a unitary structure without disturbing the secondary system.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a front view partly in elevation and partly in cross section of a refrigerating apparatus embodying features of my invention;

Fig. 2 is a view taken along the line 2+2 of Fig. 1;

Fig. 3 is a view taken along the line 3-3 of Fig. 1;

Fig. 4 is a perspective view of a portion of the apparatus shown in Fig. 1; and

Fig. 5 is a perspective view of another portion of the apparatus shown in Fig. 1.

Referring to the drawing, the. numeral designates, in general, a cabinet having a. compartment 22 for the storage of foods to be refrigerated and a low temperature or freezing compartment 23 located within the compartment 22 nearthe top and midway between the side walls thereof. The cabinet is also provided with a machine compartment 24 located below the food compartment 22. Compartment 22 is provided with an opening closed by a door 26 while compartment 23 is also provided with an opening closed by a door 28. The walls of the cabinet enclosing the food compartment 22 are insulated and include side walls 30, rear wall 3|, bottom wall 32, and top wall 33. The food compartment 22 and the low temperature compartment 23 are separated by a U-shaped partition preferably composed of heat conducting material such as sheet metal, but which, if desired, may consist of relatively poor heat conducting material. This partition is secured to the top wall 33 and rear wall 3|. An inner metallic lining member 36 forms the inner walls of the food compartment and is preferably, as is also the partition 35, provided with a coating of vitreous enamel, such as porcelain, to provide a neat appearing compartment and one which may be easily' cleaned. The machine compartment 24 is also provided with an opening at the front of the cabinet which is closed by a movable ant condensing or circulating element 4] disposed in the machine compartment 24. These elements are operatively associated with one another by a liquid supply conduit 49 in the form of a small diameter tube and a vapor return conduit 50. The entire primary refrigerating system is adapted to be removed as a unit whenever desired as will be later described.

The evaporating element 43 comprises, in general, three planar sections of serpentine conduits connected in series and are designated by the numerals 52, 53 and 54 respectively. These serpentine sections are secured in intimate heat conducting relation in any suitable 'manner as by soldering to a sheet metal framework or casing designated by the numeral 56. This framework is rigidly secured at the rear to a removcludes a U-shaped member 30 to one side of which section 52 is secured and to the bottom of which section 53 is fastened. The third section 54 is secured to the underside of plate member 8| supported within the'U-shaped member 50 intermediate its top and bottom. A sheet metal plate member 62 is secured to the U-shaped member 60 for enclosing the section 52. Section 52 is connected to the inlet refrigerant line 49 while section 54 is connected to an accumulator 63 which in turn opens into the vapor return conduit 50.

The refrigerant condensing element 41 comprises, in general, a motor compressor unit 65, condenser 66 and restricting element or small diameter tube 49. The motor compressor unit is of the type which includes a compressor and motor directly connected and enclosed within a hermetically sealed casing. Units of this type are "Well known in the art and further illustration thereof in the drawing is deemed unnecessary. The

cooling of the condensing element may be accomplished either by forced or naturalconvectior'i, the latter being the one illustrated. Air from the room circulates through the opening 4| and thence over the condensing unit. A flue, not

shown, may be provided on the rear wall of the cabinet for enhancing the natural convection effect as is well known in the art.

In operation, the compressor withdraws evaporated refrigerant. from the evaporating element through a vapor conduit 50, compresses the gaseous refrigerant and delivers it to the condenser 65 wherein .it isliquefied and from which it is delivered in liquid form to the evaporator 46 through the restricting element or supply conduit 49,which, preferably, consists of a length of capillary tubing serving to control the flow of liquid to the primary evaporator. This tubing is of proper dimensions to meter the quantity of liquid refrigerant flowing from the condensing element to the evaporating element during entire operation of the system. It is preferably secured to the vapor return conduit 50 in intimate heat exchange relation there with.

Preferably the system is intermittently operated under the control of a thermostatically controlled switch (not shown) in accordance with temperature conditions in the cabinet or either evaporating element. The temperature of the evaporating element 46 is maintained at a value sufficiently low to effect rapid freezing of ice cubes and the like andalso to maintain freezing temperatures throughout the freezing compartment 23.

Numeral i designates, in generaha secondary refrigerating system which is adapted to maintain the food compartment 22 at a relatively high and uniform refrigerating temperature and at a relatively high humidity so that little dehydration of the foods stored therein is accomplished. The secondary refrigerating system includes a cooling or evaporating element 72 and a condensing element 14. These are operatively connected by a liquid supply conduit 15 and a vapor return conduit 16. The evaporating element 12 consists preferably of a sinuous conduit formed into a continuous series of planar coils which are secured in any suitable fashion as by soldering in intimate heat conducting relationship to the outside of the metallic lining 35. The conduit runs back and forth across the bottom of the liner, then progressively upwardly, embracing three sides of the liner as shown in Fig. 4 until it reaches the top of the liner where it joins with the vapor return line I6. The condensing element 14 com-prises a serpentine conduit arranged in a vertical plane near the upper portion of the secondary m tor. This conduit is secured in intimate hat exchange relation in any suitable fashion as by bolting to the plate member 2 on the side of the primary refrigerant evaporator 48. The lesmth of conduit forming the condenser ll which actually contacts the plate 62 is determined by the difference in temperature desired between the free:- ing compartment and the food The effectiveness of the heat transfer between the condenser 14 and evaporator 45 may be cmflollcd in this manner so as to produce a temperature in the food compartment sufllciently low to properly'refrigerate the foods therein and also at the same time to prevent appreciable dehydration of the foods. The same refrigerant or a different one from that used in the primary refrigerating system may be used in the secondary system if desired. In operation, the refrigerant within the secondary system by the heat from the food compartment is carried by the return conduit 76 to the condenser ll where it is and delivered by gravity in liquid form through conduit 15 to the conduit at the bottom of the liner 36. It then circulates upwardly through the the entire food compartment is cooled to a substantially uniform temperature throughout dnce no part of the compartment is unexposed to the influence of the secondary evaporator.

Preferably the temperature of the alter walls of casing 35 is slightly lower than the temperature of liner 36 so that condensate forms chiefly if not entirely on casing 35 which may be collected readily in a drip collector which may be placed thereunder.

The primary refrigerating system is adapted to be removed as a unitary structure from the cabinet without disturbing the secondary system. The structure includes the condensing element 41, evaporating element 46 and the removable plug 58. Preferably the primary evaporating element is supported solely by the plug SI and its connection with the secondary condenser may be readily broken by unbolting the condenser from the plate 62. The condensing unit I is adapted to be removed by sliding it out through the rear opening of the machine compartment. The return vapor conduit 50 and the liquid line I! are for the most part already outside the cabinet with the exception of the portion which extant through the removal plug 58 and is accordingly removable therewith. Thus it will be seen that net having an inner liner forming a. food compartment, a secondary refrigerant evaporator surrounding a major portion of said liner for the absorption of heat through walls thereof, a casing within the food compartment to provide a freesing zone, a primary refrigerating system including a freezing portion within said freezing zone and including a condensing portion associated therewith, and a secondary condenser associated with sa d primary system for condensing evaporated refrigerant in the secondary evaporator in such a manner that the secondary evaporator operates at a temperature for cooling the air in the food storage compartment to the desired temperature with little if any moisture forming on the inner walls of said liner and said freezing portion being arranged and operated to cool the exterior walls of said casing somewhat below the temperature of the liner walls so that moisture forms chiefly if not entirely on the exterior walls of said casing.

2. Refrigerating apparatus comprising, in combination, a cabinet having its interior divided into two compartments, one within the other, a primary refrigerating system including a refrigerant condensing element and a refrigerant evaporator located in the inner compartment, and a secondary refrigerating system including a refrigerant evaporator substantially enveloping the outer compartment and a condenser located in the compartment with the primary evaporator in thermal contact therewith and at substantially the same level as the upper portion of the secondary refrigerant evaporator, said secondary system being permanently fixed in said cabinet, and said primary system being bodily removable as a unit from the cabinet without disturbing the secondary system.

3. Refrigerating apparatus comprising, in combination, an insulated cabinet, a high temperature refrigerant evaporator disposed within said cabinet and enclosing within its confines a food storage space, a refrigerant condenser connected to said high temperature evaporator, a low temperature refrigerant evaporator arranged within the confines of said first evaporator in spaced relationship therewith and separated therefrom by partitioning means, a condenser connected to said second evaporator, said second evaporator being adapted to further reduce the temperature of said food storage space, and said partitioning means being reduced to such a temperature by said second evaporator that it serves as the principal zone for condensing moisture in said food storage space.

4. Refrigerating apparatus comprising, in combination, an insulated cabinet having walls enclosing a storage chamber, a pair of partitioning members arranged to divide said chamber into a first, a second, and a third compartment, said second compartment lying between said first and third compartments, refrigerant evaporating means associated with a wall of said first compartment for maintaining a high temperature and high humidity in said first compartmenhand second refrigerant evaporating means associated with said second and third compartments for maintaining a low temperature in said second compartment, fast freezing temperatures in said third compartment and a temperature somewhat below that of said first compartments walls on the partitioning member separating said first and second compartments.

5. Refrigerating apparatus comprising, in combination, an insulated cabinet having an inner lining member forming the walls of a storage chamber, a pairof U-shaped partitioning members disposed one within the other for dividing said storage chamber into a first, a second, and a third compartment, said second compartment being arranged between said first and third compartments, secondary refrigerant evaporating means partially surrounding said first compartment for the absorption of heat through the walls thereof to maintain a high temperature and high humidity within said first compartment and primary refrigerant evaporating means secured in heat exchange relation to the U-shaped partition member separating said second and third compartmerrt for maintaining fast freezing temperatures in said third compartment, a low temperature in said second compartment and a temperature somewhat below that of said first compartments walls on the partitioning member separating said first and second compartments.

LAWRENCE A. PHILIPP, 

